Someone asked me how to mix horns combined with other instruments such as drums:

Hello, thank you so much for all the advice and tips you offer on this site…very helpful. 1 song, sounds like an old Chicago, horn driven pop tune: 2 trumpets, trombone and sax. It’s a horn driven tune. It all went into Pro tools well, plenty of bottom, horns sound great and blended them well. Let’s assume that I recorded, eq’d, and made minor cuts in each instrument. Horns are compressed. Sound great….when I turn the horns up to where you need them; the drums start to fade slightly but not badly. I can hear all the rhythm and drums still but they start to fade. How can I make them work together? Here’s where I have problems-compressing the drums. I don’t know how to do it on my own. And go by other people’s numbers. I’ve been working very hard on this one, if you did some material on mixing horns; there are tons of people on here who would listen. Horns can be tough, especially if it’s constant horns overlapping from one speaker to the next and thanks in advance.

Reply:

Thanks for your inquiry. First, your problem is most likely “masking”. This is where frequencies of different instruments overlapped each other. As a result, if one instrument increases in volume, it will dominate the other instruments in the mix resulting to fading and weakening sound of the other. In your case, you have your brass instruments and drums. If you increase the volume of these instruments; it affects other instruments such as drums. There is masking issue between these instruments. Solving the masking problem in the mix is quite simple. You need to understand the frequency ranges of those instruments are and then assign each instrument its own space in the frequency spectrum. For example below is the frequency spectrum of brass and saxophone:

You decide which instruments should occupy the different audio frequency range. The effective frequency range of audio mixing is from 35Hz (sub-bass) to 15,000Hz. No musical instruments should significantly occupy the same frequency range or else masking would occur. Supposing I have a brass instruments mix with drum kit that uses trombone in the bass, trumpet in (F-baritone) and finally saxophone for the soprano. Also I have some keyboards/organ on it. Below is my frequency assignment for these different instruments: